Stub database stream size_hint(); use proper accessor methods for cursor state.

Signed-off-by: Jason Volk <jason@zemos.net>

src/database/stream.rs

@@ -25,6 +25,10 @@ pub(crate) struct State<'a> {
 pub(crate) trait Cursor<'a, T>: Send {
 	fn state(&self) -> &State<'a>;
 
+	fn state_mut(&mut self) -> &mut State<'a>;
+
+	fn count(&self) -> (usize, Option<usize>);
+
 	fn fetch(&self) -> Option<T>;
 
 	fn seek(&mut self);
@@ -111,9 +115,15 @@ impl<'a> State<'a> {
 		}
 	}
 
-	pub(super) fn is_incomplete(&self) -> bool {
-		matches!(self.status(), Some(e) if is_incomplete(&e))
-	}
+	#[inline]
+	#[expect(clippy::unused_self)]
+	#[tracing::instrument(level = "trace", skip_all, ret)]
+	pub(super) fn count_fwd(&self) -> (usize, Option<usize>) { (0, None) }
+
+	#[inline]
+	#[expect(clippy::unused_self)]
+	#[tracing::instrument(level = "trace", skip_all, ret)]
+	pub(super) fn count_rev(&self) -> (usize, Option<usize>) { (0, None) }
 
 	#[inline]
 	fn fetch_key(&self) -> Option<Key<'_>> { self.inner.key() }
@@ -124,6 +134,10 @@ impl<'a> State<'a> {
 	#[inline]
 	fn fetch(&self) -> Option<KeyVal<'_>> { self.inner.item() }
 
+	pub(super) fn is_incomplete(&self) -> bool {
+		matches!(self.status(), Some(e) if is_incomplete(&e))
+	}
+
 	#[inline]
 	pub(super) fn status(&self) -> Option<rocksdb::Error> { self.inner.status().err() }
 

src/database/stream/items.rs

@@ -24,10 +24,16 @@ impl<'a> Cursor<'a, KeyVal<'a>> for Items<'a> {
 	fn state(&self) -> &State<'a> { &self.state }
 
 	#[inline]
-	fn fetch(&self) -> Option<KeyVal<'a>> { self.state.fetch().map(keyval_longevity) }
+	fn state_mut(&mut self) -> &mut State<'a> { &mut self.state }
 
 	#[inline]
-	fn seek(&mut self) { self.state.seek_fwd(); }
+	fn count(&self) -> (usize, Option<usize>) { self.state().count_fwd() }
+
+	#[inline]
+	fn fetch(&self) -> Option<KeyVal<'a>> { self.state().fetch().map(keyval_longevity) }
+
+	#[inline]
+	fn seek(&mut self) { self.state_mut().seek_fwd(); }
 }
 
 impl<'a> Stream for Items<'a> {
@@ -36,9 +42,11 @@ impl<'a> Stream for Items<'a> {
 	fn poll_next(mut self: Pin<&mut Self>, _ctx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
 		Poll::Ready(self.seek_and_get())
 	}
+
+	fn size_hint(&self) -> (usize, Option<usize>) { self.count() }
 }
 
 impl FusedStream for Items<'_> {
 	#[inline]
-	fn is_terminated(&self) -> bool { !self.state.init && !self.state.valid() }
+	fn is_terminated(&self) -> bool { !self.state().init && !self.state().valid() }
 }

src/database/stream/items_rev.rs

@@ -24,10 +24,16 @@ impl<'a> Cursor<'a, KeyVal<'a>> for ItemsRev<'a> {
 	fn state(&self) -> &State<'a> { &self.state }
 
 	#[inline]
-	fn fetch(&self) -> Option<KeyVal<'a>> { self.state.fetch().map(keyval_longevity) }
+	fn state_mut(&mut self) -> &mut State<'a> { &mut self.state }
 
 	#[inline]
-	fn seek(&mut self) { self.state.seek_rev(); }
+	fn count(&self) -> (usize, Option<usize>) { self.state().count_rev() }
+
+	#[inline]
+	fn fetch(&self) -> Option<KeyVal<'a>> { self.state().fetch().map(keyval_longevity) }
+
+	#[inline]
+	fn seek(&mut self) { self.state_mut().seek_rev(); }
 }
 
 impl<'a> Stream for ItemsRev<'a> {
@@ -36,9 +42,11 @@ impl<'a> Stream for ItemsRev<'a> {
 	fn poll_next(mut self: Pin<&mut Self>, _ctx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
 		Poll::Ready(self.seek_and_get())
 	}
+
+	fn size_hint(&self) -> (usize, Option<usize>) { self.count() }
 }
 
 impl FusedStream for ItemsRev<'_> {
 	#[inline]
-	fn is_terminated(&self) -> bool { !self.state.init && !self.state.valid() }
+	fn is_terminated(&self) -> bool { !self.state().init && !self.state().valid() }
 }

src/database/stream/keys.rs

@@ -24,10 +24,16 @@ impl<'a> Cursor<'a, Key<'a>> for Keys<'a> {
 	fn state(&self) -> &State<'a> { &self.state }
 
 	#[inline]
-	fn fetch(&self) -> Option<Key<'a>> { self.state.fetch_key().map(slice_longevity) }
+	fn state_mut(&mut self) -> &mut State<'a> { &mut self.state }
 
 	#[inline]
-	fn seek(&mut self) { self.state.seek_fwd(); }
+	fn count(&self) -> (usize, Option<usize>) { self.state().count_fwd() }
+
+	#[inline]
+	fn fetch(&self) -> Option<Key<'a>> { self.state().fetch_key().map(slice_longevity) }
+
+	#[inline]
+	fn seek(&mut self) { self.state_mut().seek_fwd(); }
 }
 
 impl<'a> Stream for Keys<'a> {
@@ -36,9 +42,11 @@ impl<'a> Stream for Keys<'a> {
 	fn poll_next(mut self: Pin<&mut Self>, _ctx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
 		Poll::Ready(self.seek_and_get())
 	}
+
+	fn size_hint(&self) -> (usize, Option<usize>) { self.count() }
 }
 
 impl FusedStream for Keys<'_> {
 	#[inline]
-	fn is_terminated(&self) -> bool { !self.state.init && !self.state.valid() }
+	fn is_terminated(&self) -> bool { !self.state().init && !self.state().valid() }
 }

src/database/stream/keys_rev.rs

@@ -24,10 +24,16 @@ impl<'a> Cursor<'a, Key<'a>> for KeysRev<'a> {
 	fn state(&self) -> &State<'a> { &self.state }
 
 	#[inline]
-	fn fetch(&self) -> Option<Key<'a>> { self.state.fetch_key().map(slice_longevity) }
+	fn state_mut(&mut self) -> &mut State<'a> { &mut self.state }
 
 	#[inline]
-	fn seek(&mut self) { self.state.seek_rev(); }
+	fn count(&self) -> (usize, Option<usize>) { self.state().count_rev() }
+
+	#[inline]
+	fn fetch(&self) -> Option<Key<'a>> { self.state().fetch_key().map(slice_longevity) }
+
+	#[inline]
+	fn seek(&mut self) { self.state_mut().seek_rev(); }
 }
 
 impl<'a> Stream for KeysRev<'a> {
@@ -36,9 +42,11 @@ impl<'a> Stream for KeysRev<'a> {
 	fn poll_next(mut self: Pin<&mut Self>, _ctx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
 		Poll::Ready(self.seek_and_get())
 	}
+
+	fn size_hint(&self) -> (usize, Option<usize>) { self.count() }
 }
 
 impl FusedStream for KeysRev<'_> {
 	#[inline]
-	fn is_terminated(&self) -> bool { !self.state.init && !self.state.valid() }
+	fn is_terminated(&self) -> bool { !self.state().init && !self.state().valid() }
 }